Electroporation has become the preferred method for gene transfer due to its ease and efficiency of operation in comparison to alternate techniques. To date, electroporation has been utilized to transform a wide variety of cell types including mammalian cells, plant protoplasts, bacteria and fungi, including yeast. The technique involves subjecting cells to a high voltage electric field, which results in the temporary formation of pores in the membrane, thereby allowing exogenous DNA to enter the cells. For example, laboratory strains of the yeast Saccharomyces cerevisiae have been transformed by electroporation with either self-replicating plasmids or by integration of linearized plasmid DNA into the host genome.
Candida albicans is a pathogenic, diploid yeast capable of causing a broad spectrum of infections, especially in immunocompromised individuals. As the number of persons with increased susceptibility to Candida has risen over the past decade, so has the importance of this organism as an agent of disease. Much work has been done on this organism to identify potential virulence factors and to study its biology. To further the understanding of C albicans biology at the molecular level, a number of transformation systems have been developed. Integrative transformation was the first method developed for the transformation of C. albicans (Kurtz et al., Mol. Cell. Biol. (1986) 6:142-149). It is now widely used for genetic manipulation. Other references regarding transformation of Candida albicans include Kelly et al. Mol. Cell. Biol. (1987) 7:199-207; Kurtz et al. Mol. Cell. Biol. (1987) 7:209-217; Kelly et al. Mol. Gen. Genet. (1988) 214:24-31; Cannon et al., Mol.. Gen. Genet. (1990) 235:4453-457; A recent journal article, Brown et al., Mol. Gen. Genet. (1996) 251:75-80, discloses a transformation method for C. albicans using restriction enzyme-mediated integration.